Method of producing electroluminescence emitting film

Abstract

A method of making electroluminescence emitting films each containing sulfide such as Sr, Ca, etc. as a base material and a rare earth element such as Ce, Eu, Pr, etc. as an emitting center by sputtering method, so that the electroluminescence emitting film can produce with high luminance and with various emission light colors. In the method, an element such as Sr to be sulfidized for a base material is used as a target. A sputtering gas such as Argon to be supplied to a sputtering apparatus is mixed with an H 2 S gas as a base material sulfur compound. A rare earth element compound such as tris-cyclopentadienyl-cerium for an emitting center is gasified by a gas generator while being heated under supply of a carrier gas such as Ar, so that the gasified rare earth element compound is added to the sputtering gas. In the abovementioned condition, an electroluminescence emitting film is produced on a display panel by a high frequency sputtering method in a sputtering atmosphere of the sputtering gas containing sulfur for the base material and a rare earth element for the emitting center.

What is claimed is: 
     
       1. A method of producing an electroluminescence emitting film comprising: sputtering an elemental target in a reactive atmosphere, wherein said target comprises an element to be sulfidized and said reactive atmosphere comprises an inert sputtering gas, a sulfur compound gas and a gasified compound of a rare earth element;   reactively depositing an electroluminescence emitting film including said rare earth and sulfur from said reactive atmosphere.   
     
     
       2. A method of producing an electroluminescence emitting film as claimed in claim 1, wherein said electroluminescence emitting film includes a material selected from a group consisting of SrS, CaS, and ZnS. 
     
     
       3. A method of producing an electroluminescence emitting film as claimed in claim 1, wherein said rare earth element as an emitting center is selected from a group consisting of Ce, Eu, and Pr. 
     
     
       4. A method of producing an electroluminescence emitting film as claimed in claim 1, said sulfur compound gas to be mixed with said inert sputtering gas is selected from a group consisting of H 2  S, CS 2 , S(CH 3 ) 2 , and S(C 2  H 5 ) 2 . 
     
     
       5. A method of producing an electroluminescence emitting film as claimed in claim 3, wherein said compound of said rare earth element is selected from a group consisting of Ce compounds, Eu compounds and Pr compounds. 
     
     
       6. A method of producing an electroluminescence emitting film as claimed in claim 5, wherein said compound of said rare earth element is selected from a group consisting Ce(C 5  H 5 ) 3 , Ce(C 11  H 20  O 2 ) 3 , Ce(OCH 3 ) 3 , Ce chloride, Ce fluoride, Eu(C 11  H 20  O 2 ) 3 , Eu chloride, Eu fluoride, Eu sulfide, Pr(C 11  H 20  O 2 ) 3 , Pr chloride, Pr fluoride, and Pr sulfide.